1. Field of The Invention
This invention relates to new and improved automated liquid dilution apparatus and method which are particularly adapted for use with automated sample liquid analysis systems.
2. Description of the Prior Art
U.S. Pat. No. 4,049,381 issued Sept. 20, 1977 to Donald A. Burns, Ph.D., et al, for Apparatus And Method of Fluid Sample Analysis, and assigned to the assignee hereof, discloses dilution apparatus and method directed to the preparation of concentration gradients in liquid samples; and, to this effect, comprises means for diluting a reagent liquid with an appropriate diluent liquid to a varying degree prior to the combination of the thusly diluted reagent liquid with a sample liquid. This dilution is achieved by withdrawing reagent liquid from a reagent liquid supply conduit at a varying flow rate, replacing the thusly withdrawn reagent liquid downstream in the supply conduit with a diluent liquid at substantially the same varying flow rate, and mixing the thusly variably diluted reagent liquid with a sample liquid for subsequent quantitative sample liquid analysis with regard to sample liquid constituent of interest.
The turbidometric assay system marketed by the Elanco Products Co., division of Eli Lilly Co., Indianapolis, Ind., under the Trademark "Autoturb" is designed to analyze the potency of antibiotics, vitamins and related substances; and, to this effect, includes a diluter module which functions to dilute sample liquids in sample liquid conduit lengths, or loops, of different volumes by introducing a selected one of those sample liquid volumes to a carrier stream which contains a fixed proportion of a diluent liquid. Thus, the extent to which the sample liquid is diluted by the diluent liquid in the carrier stream will be determined in accordance with the selected sample liquid volume which is introduced into the carrier stream. This system is described in Elanco's sales brochure entitled AUTOTURB II.